As stored-program controlled switching systems have evolved, a wide variety of useful features have been developed to extend the communication capabilities such systems provide. For example, a well-known call forwarding feature enables a customer to receive incoming calls at another location by activating the call fowarding service and providing a forward-to directory number to the switching system. A call transfer service allows a called party to tranfer incoming calls appropriately based on brief conversations with the calling parties.
Although both call forwarding and call transfer are very useful in many applications, consider the following scenario. A senior sales repesentative has developed a loyal customer following over a period of several years. Since he now has more customers than he can handle effectively, he would prefer to have incoming calls from most of his customers handled by several associates, at least during busy times. He could activate call forwarding, but then all his calls would be forwarded, including personal calls as well as calls from his most important customers. A further disadvantage is that all calls would be forwarded to only one of his associates. Alternatively, he could answer all incoming calls himself and transfer them to his associates only when appropriate. Not only would this be time consuming, but in addition, many of his customers tend to engage in long conversations and would be offended by being transferred abruptly, particularly knowing that the representative they called is transferring them but remains available to answer other incoming calls.
In view of the foregoing, a call forwarding feature is needed that allows a called party to exercise discretion in forwarding individual calls based, for example, on the calling party identity or on how busy the called party is at any given time, but without requiring the called party to first answer the calls. It would also be highly desirable to allow the called party to effect the forwarding even though presently engaged in conversation with someone else.